Tisztelt Kollégák,
2019. október 4-én du. 4 órakor Jakob Pietschnig (Bécsi Egyetem) előadást tart a az ELTE-n
“ Inflated effects in empirical research are ubiquitous but become smaller over time:
Meta-meta-analytical evidence for the decline effect ” címmel. Az előadás helyszíne: ELTE
PPK, Kazinczy u. 23-27., fszt. 4., az absztrakt megtalálható a levél alján. Minden
érdeklődőt szeretettel várunk.
Üdvözlettel,
Kovács Kristóf
Inflated effects in empirical research are ubiquitous but become smaller over time:
Meta-meta-analytical evidence for the decline effect
Principles of a-priori hypothesizing, care- and thoughtful study design, and effect
corroboration by direct replication are standards that ensure the meaningfulness of
obtained results in empirical research and that are embraced by virtually all empirical
researchers. Recently, however, the trust in empirical research in general and
Psychological Science in particular has been undermined by unreliable effect estimates,
biased results, and lacking reproducibility. Strategic researcher behaviors and
publication process-related mechanisms that promote the publication of striking (but
wrong) or inflated results were frequently cited as potential drivers for effect
invalidity and misrepresentations. Although effect declines have been documented in a
number of specific cases in the literature, no systematic account of effect changes over
time is to date available. Consequently, in this presentation, I provide evidence for
cross-temporal effect changes (regardless of the respective research question) based on
more than 400 meta-analyses (N = 270,000,000+; k = 28,000+) that have been published in
five flagship journals in Psychology. On the whole, analyses of effect trajectories
indicate average effect changes of about a small effect size (i.e., r = .10) for every 15
years that elapsed following their initial publication (i.e., the first account that has
been published for a given research question). Importantly, the aggregated evidence shows
that effect declines outnumber increases at a ratio of about 3:2 and are on average twice
as strong. Moreover, larger exploratory and summary effects appear to be associated with
more substantial effect declines. Remedies for such systematic ubiquitous effect
misrepresentations warrant changes in scientific quality control (i.e., the review
process) and the evaluation of academics (e.g., in terms of tenure or promotion
committees). Promoting study preregistration, the publication of primary data, discovery-
and replication-sampling approaches, as well as the use of safeguard power in replications
may be first steps in the right direction.